JP4204686B2 - Reamer system for elliptical acetabulum - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reamer system, and more particularly to a system for drilling bone in preparation for implantation of a prosthetic portion such as an acetabular cup.
[0002]
[Background Art and Problems to be Solved by the Invention]
Arthroplasty is a well-known surgical procedure that replaces a diseased and / or impaired natural joint with a prosthetic joint. Arthroplasty is typically performed on the hips, knees, elbows and other joints. The health and disease of the joint to be replaced dictates the type of prosthesis needed to replace the natural joint.
[0003]
In all hip arthroplasty, the crotch cup is embedded in the pelvic crotch, replacing the natural acetabulum. A variety of joint diseases, such as when the articular surface of the femoral prosthesis head or ball is inadequate, requires acetabular replacement. Also, all hip arthroplasty is justified in certain cases of stunted hips (DDH) where natural acetabular depressions are not properly formed and sufficient articulation is not possible.
[0004]
A hole is drilled in the acetabulum to embed the acetabular cup. The acetabular cup is then inserted into the formed hole and secured by mechanical means, interference fit or a combination thereof. The acetabular cup must be placed on the pelvis in a fixed orientation relative to the patient's body and remain stable.
[0005]
If the acetabular hole is not entirely spherical, an elliptical acetabular cup may need to be embedded. Examples of such cases are joint diseases in which an implanted acetabular cup (typically a hemispherical cup) moves upwards and certain types of DDH. The oval shape of the cup is compatible with the long acetabular hole. One type of elongated acetabular cup has an outer contour formed by two adjacent hemispheres. As an example, two hemispherical acetabular cups 10 are shown in FIGS. 1 (A) and 1 (B). The cup 10 has an outer surface 12 formed by a first main hemisphere 14 with a second hemisphere 16. The main hemisphere forms the main surface 18 and the second hemisphere forms the second surface 19. The main hemisphere 14 has a recessed inner surface 17. Inner surface 17 receives a thigh head or liner that can receive a ball.
[0006]
When such an elliptical acetabular cup secures the prosthesis with an interference fit alone, it is important that the holes be formed within precise dimensional tolerances. If a proper fit is not achieved, the interference fit acetabular cup will not lock in the acetabulum for an extended period of time. However, it is difficult to achieve the level of accuracy required when drilling acetabular holes using conventional instruments.
[0007]
To embed an elliptical acetabular cup, a acetabular hole is typically formed in two separate stages. Initially, a true (also known as the main or original) acetabular hole is formed. Generally, the surgeon aligns a conventional reamer / driver instrument with the acetabulum and drills the main or original hole into a hemisphere. FIG. 2 is a view showing a conventional reamer / driver device 20 for making an original acetabular hole 22 in the acetabulum 24. Forming the original acetabular cavity with the reamer / driver device 20 is a relatively straight forward process. However, in order to form an auxiliary or missing hole for the elliptical cup 10, the already formed original hole 22 is used as a reference point to provide a hole that matches the outer surface 12 of the elliptical cup 10. There must be.
[0008]
FIG. 3 shows one type of prior art instrument. This is known as the basket reamer / driver 30 and is used to open an auxiliary acetabular hole after making a true acetabular hole. As used herein, “reamer / driver” refers to the instrument as a whole, and “reamer” refers to a rotating head that removes tissue. The device 30 includes an arcuate guide 32 for placement in the drilled natural hole and a reamer 34 for removing bone tissue. The reamer 34 can be connected to a power drill mechanism that rotates the reamer.
[0009]
To form an auxiliary acetabular hole, the surgeon first identifies where the auxiliary hole should be formed with the eye. The auxiliary or defect hole is formed in the vicinity of the periphery of the original acetabular hole 22 (see FIG. 2). After placing the guide 32 in the original drilled hole, the surgeon rotates the reamer 34 in the direction of the area to be drilled to form an auxiliary acetabular hole. However, since the reamer rotates to form a defect hole, it is difficult to hold the instrument in alignment with the acetabulum. Furthermore, it is not clear when the desired amount of bone is removed. Thus, it is difficult to form the two hemispherical acetabular holes with the accuracy required to secure the elliptical interference fit acetabular cup for a long period of time.
[0010]
Another disadvantage of the known basket reamer / driver device is the lack of modularity in the various components. Generally, a hole is drilled using a reamer that grows continuously. Each reamer is coupled to a separate reamer / driver device sized to receive a given reamer. Thus, the reamer / driver can only form one size hole, and several reamer / driver devices are required to prepare the acetabular hole in the acetabulum.
It is desirable to provide a modular reamer system to form a complex shaped hole that fits exactly to the outer surface of an elliptical acetabular cup.
[0011]
[Means for Solving the Problems]
The present invention provides a reamer system for accurately forming holes having a complex profile. Although the present invention will be described primarily with respect to opening an acetabulum for embedding an elliptical acetabular cup, it is understood that the present invention has other uses.
In one embodiment, the reamer system is particularly useful for forming a second hole relative to the first hole in the acetabulum for embedding an acetabular cup having two hemispheric outer surfaces. The reamer system includes a reamer / driver instrument with a bearing plate, the bearing plate having a first portion that connects to the distal end of the handle and a second portion that connects to an elongate drive member. The proximal end of the handle facilitates instrument placement. The drive member has a distal reamer coupling end and a proximal end coupled to a mechanism for rotating the distal reamer coupling end of the drive member. The far reamer coupling end can move axially toward and away from the far face of the bearing plate, forming a second hole. The system further includes at least one position locating member that is detachably and replaceably attached to the distal end of the bearing plate and has a distal reamer coupling end associated with the previously formed first hole. Deploy.
[0012]
In yet another embodiment, the system includes a plurality of reamers, each reamer having a different outer dimension and an inner surface that can be coupled to a distal reamer coupling end of one drive member. The reamer and the drive member provide a modular reamer system capable of increasing the size of the hole by continuously attaching a reamer having an increased external dimension to the drive member.
[0013]
In yet another embodiment, the reamer system includes a plurality of position location members, each location location member having a geometric shape that corresponds to an individually sized reamer. In an exemplary embodiment, each location-finding member has a base portion that can be coupled to a bearing plate and an upper portion having an outer surface at least partially forming a portion of a sphere. The arcuate outer surface is disposed within the hemispheric inner surface of the already formed first hole. Each locator member has a shape that is effective for positioning a separate reamer such that the second hole is formed in conformity with a corresponding portion of the elliptical acetabular cup to be embedded.
[0014]
In yet another embodiment, the system includes a guide member that can be secured to the handle that provides an indication of the abduction and anteversion angle of the drive member relative to the patient. In an exemplary embodiment, the guide member has a leg, and the leg has first and second arms that extend from one end of the leg. The other end of the leg can be coupled to the handle so that the guide member can rotate about the long axis of the handle. Depending on the orientation of the legs and arms of the guide member with respect to the patient, visual indications of the abduction and forward tilt angles for making the second hole are given.
[0015]
Assemble the instrument by selecting a reamer to form a second hole of the desired size and securing the reamer to the distal reamer coupling end of the drive member. Thereafter, the corresponding position finding member is attached to the bearing plate. A guide member is coupled to the handle and a proximal end of the drive member is coupled to the drill mechanism.
[0016]
In order to form the hole, the position search member is placed in the first hole already formed. The guide member provides a visual indication of the abduction and forward tilt position of the instrument to the patient. As known to those skilled in the art, the angle of abduction is measured on a transverse plane that divides the body into upper and lower parts. The anteversion angle is measured on the coronal suture or frontal plane that forms the boundary between the front and back parts of the body. In one embodiment, the instrument is positioned at a predetermined abduction angle when the patient lies horizontally and the guide member legs are vertical. The instrument is positioned at a predetermined anteversion angle when the long axis of the drive member is aligned with the tip of either the first or second arm of the guide member.
[0017]
The surgeon then determines the location where the second or defect hole is to be formed. The instrument is rotated around the first or true acetabular hole (using the location member in the first hole) while maintaining the abduction and forward tendency of the instrument. The guide member is rotatable about the long axis of the handle to facilitate instrument positioning and puncture the second hole while maintaining alignment of the main hemispherical face of the implant. After placement of the instrument, the drive member is moved axially away from the bearing plate to form a defect hole except for the tissue. In this way, a complex geometrically shaped hole is precisely formed in the acetabulum to accommodate the two acetabular acetabulums.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be more fully understood from the following detailed description with reference to the drawings.
FIGS. 4 to 13 show, as an example, a reamer system 100 that includes an instrument 102, which includes an elongate handle that couples to a drive member 104 that can be coupled to a reamer 106 and a bearing plate 110. 108. The location member 113 extends from the bearing plate 110 into a hole already formed for insertion to place the instrument 102. As will be described below, the reamer system 100 provides an auxiliary or defective acetabular hole in the acetabulum 24 relative to the main hole 22 already formed for embedding the elliptical acetabular cup 10 (see FIG. 1). It is particularly useful for forming.
[0019]
The handle 108 has a proximal end 112 with a handle grip 114 to facilitate placement of the instrument 102. The distal end 116 of the handle is secured to the first portion 118 of the bearing plate. The handle 108 can be coupled to the bearing plate 110 using various engagement mechanisms. The engagement may be released by the engagement mechanism, may be engaged permanently, or a combination thereof. In one embodiment, the distal end 116 of the handle is insertable into a bore 120 (see FIG. 10) formed in the handle engagement portion 122 extending from the proximal surface 124 of the bearing plate. A thread 126 formed on the distal end 116 of the handle can engage a thread 128 formed on the inner surface of the bore, and the handle 108 can be threadedly engaged with the bearing plate 110.
[0020]
The bearing plate 110 has a second portion 130 with a drive member guide 132 extending from the proximal surface 124 of the bearing plate. The bore 134 (see FIG. 10) extends through the drive member guide 132 with a bearing 136 (see FIG. 12) at least partially within the bore. The drive member guide part 132 and the bearing 136 fix the drive member 104 at a fixed angle with respect to the handle 108, and allow the drive member to move in the axial direction and the rotational direction with respect to the bearing plate 110.
[0021]
As shown in FIG. 12, the second portion 130 of the bearing plate extends from the first portion 118 at an angle A. An angled bearing plate 110 positions the handle 108 and the drive member 104 at an angle A. As will be described below, this angle corresponds to the angle formed by the first and second surfaces of the acetabulum. The angle A of the first portion 118 and the second portion 130 of the bearing plate can vary from about 0 degrees to about 45 degrees, more preferably from about 15 degrees to about 20 degrees.
[0022]
The drive member 104 has a distal reamer coupling end 136 that extends from the distal surface 138 of the bearing plate. The reamer 106 can be selectively coupled to the distal end 136 so that the reamer can quickly engage and disengage from the drive member 104. In the exemplary embodiment shown here, the distal reamer coupling end 136 ends with an annular mounting plate 140, which easily engages the reamer 106. The reamer 106 is attached to the plate 140 under an axial pressure, and is removed by operating the bias release switch 142 (see FIG. 10). However, it will be understood that those skilled in the art can readily modify the reamer coupling mechanisms 140, 142 described herein.
[0023]
The collar 144 is fixed to the driving member 104 at a predetermined distance from the distal end of the far reamer coupling end 136. The collar 144 is effective to limit axial movement of the far reamer coupling end 136 away from the far face 138 of the bearing plate. In particular, with the maximum extension of the reamer 106 (see FIG. 5), the collar 144 contacts the drive member guide 132 of the bearing plate. When the reamer 106 is fully retracted (see FIG. 4), the collar 144 is positioned at a selected distance from the drive member guide 132 and the drive member's remote reamer coupling end 136 is adjacent to the bearing plate 110. It is in.
[0024]
The proximal end 146 of the drive member is connected to a conventional drill mechanism (not shown) to rotate the drive member 104 and reamer 106. Such drilling mechanisms are well known to those skilled in the art.
The drive member 104 may include various components that allow the reamer 106 to rotate or extend away while maintaining the drive member at a fixed angle with respect to the bearing plate 110 and the handle 108. it can. In the example embodiment shown in FIG. 11, the drive member 104 includes an inner member 148 that rotates within a concentric outer member 150.
[0025]
In particular, as shown in FIGS. 6, 7, 10, and 13, the position search member 113 has a base portion 152 and an upper portion 154, and the base portion 152 can be coupled to the far surface 138 of the bearing plate 110, and the upper portion 154 is formed. And an outer surface 156 shaped to mate with a true acetabular hole. As will be described in more detail below, the position search member 113 arranges the reamer 106 so that the auxiliary acetabular hole is formed with reference to the position already formed by the true acetabular hole. In an exemplary embodiment, the outer surface 156 of the location member forms part of a sphere that mates with a spherical hole formed by the reamer 106. In an exemplary embodiment, the long axis of the handle 108 is aligned with a spherical center formed in part by the outer surface 156 of the location member.
[0026]
In addition, the upper portion 154 of the position finding member has an arcuate inner surface 157. The inner surface 157 is substantially depressed so that the position search member 113 does not interfere with the reamer 106. It is important that the reamer 106 can extend axially from the bearing plate 110 without contacting the position location member 113. In order for the removed tissue to escape the rotating reamer, the inner surface 157 must be sized to provide adequate space from the reamer 106.
[0027]
The base portion 152 of the position search member has an end surface 158. End face 158 has first and second posts 160a, 160b (see FIG. 13) extending therefrom. The post 160 can be inserted into corresponding first and second bores 162 in the first portion of the bearing plate 110. The post 160 is precisely positioned and positions the outer surface 156 of the position location member relative to the drive member 104 and the reamer 106.
[0028]
The position search member 113 can be fixed to the bearing plate 110 using various coupling mechanisms. Examples of coupling mechanisms include fasteners such as nuts, bolts, interference fits and other removable mechanisms. In the illustrated embodiment, the position search member 113 can be secured to the bearing plate using a retaining screw 164. The holding screw 164 enters the muscle bore 165 of the corresponding position search member 113 through the opening of the bearing plate 110.
[0029]
The reamer system 100 can also include a guide mechanism 166 for providing forward tilt and abduction information to the operator. In an exemplary embodiment, the guide mechanism 166 includes a guide member 168 with first and second arms 172a, 172b and legs 170 forming a V shape. As shown, the arm 172 is perpendicular to the leg 170. The distal end 174 of the leg is insertable into a bore formed in the alignment block 176 that connects to the handle 108. As described below, when the reamer is positioned to form a defect hole, the alignment block 176 can rotate about the long axis of the handle 108.
[0030]
The bores in the alignment block 176 are formed such that the legs 170 extend from the alignment block and form an angle C (see FIG. 6) of about 135 degrees with respect to the handle. An exemplary desired abduction angle of about 45 degrees is achieved when the patient lies on the operating table and the arm 172 is horizontal. As known to those skilled in the art, the abduction angle is determined relative to the midline transverse plane.
[0031]
As shown in FIG. 9, the first and second arms 172a and 172b of the guide form an angle D of about 40 degrees as an example. Angle D branches into two 20 degree parts, giving a forward tilt angle of about 20 degrees when forming the auxiliary acetabular hole. As known to those skilled in the art, the anteversion angle is a measurement relative to the coronary suture or the frontal plane. The arm 172 functions as a guide to the operator when orienting the reamer / driver. In particular, the drive member 104 is axially aligned with one end of the arm 172 and forms a forward tilt of about 20 degrees when forming an auxiliary acetabular hole.
[0032]
In another embodiment shown in FIG. 14, the reamer system 100 of the present invention is modular including a series of different sized reamers 106a-106f. Each reamer 106 has an outer dimension for making a special sized hole. The reamer system 100 requires a single reamer / drive device 102 that can be coupled to each reamer 106. Thus, the reamer / drive is not limited to forming a predetermined size hole as in prior art reamer devices.
[0033]
Further, as shown in FIG. 15, the system 100 can include a series of position search members 113a and 113b having different sizes. Although two location members 113 are illustrated, it can be appreciated that the system can include any number of reamers and location members. Each location member 113 corresponds to a reamer 106 used to form a specially sized acetabulum and / or auxiliary acetabular hole to be implanted. As the size of the two hemispherical acetabulums increases, the corresponding position exploration member 113 also increases in size and places the reamer 106 at the desired position. That is, for each size of acetabular cup implant, the corresponding position finding member 113 provides a reference point for forming an auxiliary acetabular hole with respect to the vacated true acetabular hole.
[0034]
Depending on the shape of the location member 113, the collar 144 is not required to adjust for each reamer or acetabular cup. The location member 113 is formed so that the maximum reamer extension determined by the collar 144 corresponds to the desired reamer and desired depth of the acetabular cup.
[0035]
The overall dimensions of the reamer / driver and the various components can be varied to obtain the desired shape of the original and defect holes to match the outer surface of the individual acetabulum. Those skilled in the art will appreciate that the exemplary shapes and dimensions described herein can be readily varied.
Examples of the outer surface radius of the reamer 106 are 45, 48, 51, 54, 57, 60, 63 millimeters. Corresponding location member 113 has a spherical outer surface 156 formed with a radius of about 20 millimeters to about 40 millimeters.
[0036]
The above dimensions are exemplary and it will be understood by those skilled in the art that the particular embodiments shown and described herein can be readily modified without departing from the scope and spirit of the invention.
The two acetabulum holes are prepared in an exemplary continuous process to receive the acetabulum. Initially, the patient's acetabular area is assessed using x-rays to determine the acetabular shape and to discover any anatomical abnormalities, dysplasias and / or leg length discrepancies. Thereafter, pre-treatment measurements can be performed to determine the size of the acetabulum to be implanted.
[0037]
In order to form a hole that fits the complex shape of an elliptical acetabular cup, two separate drilling steps are performed. First, the original or true acetabulum hole 22 is formed in the acetabulum 24 (see FIG. 2). This hole is drilled using a conventional reamer / driver instrument 20 known to those skilled in the art. The formed original acetabular hole 22 is hemispherical to receive the main portion of the corresponding elliptical acetabular cup.
Auxiliary or defective acetabular holes are formed using the reamer system 100 of the present invention. The auxiliary acetabular bore corresponds to the second or elongated portion 16 of the elliptical acetabular implant (see FIG. 1). The auxiliary acetabular hole must be positioned relative to the already evacuated original acetabular hole and formed within accurate dimensional tolerances. Proper positioning and shape of the auxiliary acetabular hole provides a reliable interference fit to the implant and allows for long-term fixation of the implanted acetabular cup.
[0038]
As described above, based on the size of the oval acetabular cup to be embedded, the corresponding reamer 106 and position search member 113 are selected and fixed to the instrument 102. The surgeon then visually determines the location of the auxiliary acetabular hole.
It will be appreciated that the true acetabular hole must be oriented so that the main portion 14 of the acetabular cup is properly aligned to receive the femoral head. The acetabular cup 10 must be implanted to provide an optimal range of motion for the patient's thigh and to reflect the anatomical joints to the extent possible. Accordingly, the auxiliary acetabular hole must be formed to receive the second portion 16 of the elliptical acetabular cup with reference to the true acetabular hole.
[0039]
The instrument 102 is arranged with respect to the formed original acetabular hole by disposing the position searching member 113 in the already formed original acetabular hole 22. The guide 166 is used to manipulate the instrument to a position of about 45 degrees of abduction and about 20 degrees of forward tilt. In particular, the guide leg member 170 must extend vertically (see FIG. 6), and the first or second arm 172a, 172b of the guide must align with the long axis of the drive member 104 (see FIG. 9).
[0040]
While maintaining the desired anteversion and abduction orientation, the handle 104 is rotated about the true acetabulum until the reamer 106 is aligned with the desired position for the auxiliary acetabulum. During rotation, the alignment block 176 rotates around the handle 106 to maintain the anteversion / abduction orientation, ie, the orientation of the major surface of the elliptical implant. The locating member's spherical outer surface 156 rotates easily within the formed spherical original acetabular hole and provides a reference point for opening an auxiliary acetabular hole.
[0041]
At this point, the instrument 102 has the desired anteversion and abduction orientation and the reamer 106 is aligned with the location of the auxiliary acetabular hole to be formed. Thereafter, a drive mechanism (not shown) is operated to rotate the drive member 104 and the reamer 106. The operator applies axial pressure to the drive mechanism 104 and extends the reamer 104 in the distal direction along the long axis of the drive mechanism, i.e. away from the bearing plate 110. The forward tilt / abduction position of the instrument 102 is maintained during the drilling process. The reamer 106 continues to extend far until the collar 144 contacts the drive member guide 132 of the bearing plate. The reamer's plunger-type movement creates an auxiliary acetabular hole with the correct depth and shape.
[0042]
The complex shaped hole is then evaluated using an elliptical trial implant and inserted into the hole forming the acetabular cup by known surgical methods.
One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are hereby incorporated by reference in their entirety.
[0043]
  A preferred embodiment is shown below.
(I) an elongated handle having a proximal end and a distal end;
  A bearing plate having a first portion and a second portion coupled to the handle and further including a near surface and a distant surface;
  At least one position finding member removably and replaceably attached to the bearing plate;
  An elongate drive member coupled to the second portion of the bearing plate;
  The drive member has a distant reamer coupling end and a proximal end coupled to a drive mechanism for rotating the drive member;
  A reamer system that forms a second hole in relation to the first hole, wherein the distal reamer coupling end can move axially toward and away from the far surface of the bearing plate.
  (1) Furthermore, it includes a mounting plate at the distal end of the driving member, and the mounting plate can be coupled to the reamer.Embodiment (I)The system described in.
  (2) Further, the reamer includes a plurality of reamers, each reamer having a different outer size and an inner surface that can be coupled to a distal reamer coupling end of the drive memberEmbodiment (I)The system described in.
  (3) At least one of the plurality of reamers has a substantially hemispherical outer surface.Embodiment (I)The system described in.
  (4) The system according to embodiment (2), wherein there are a plurality of position search members of different sizes.
  (5) The system according to the embodiment (4), wherein each of the plurality of position search members has a shape corresponding to each one of the plurality of reamers, and the reamer is disposed at a desired position.
[0044]
  (6) The position search member has a near portion coupled to the bearing plate and a distant portion having an outer surface, and at least a part of the outer surface is substantially spherical.Embodiment (I)The system described in.
  (7) The system of embodiment (6), wherein the long axis of the handle is aligned with the center of the sphere.
  (8) The system according to embodiment (6), wherein the proximal end of the location member includes at least one mounting post insertable into a bore formed in the bearing plate.
  (9) Further, in order to limit the movement of the far end reamer coupling end of the drive member away from the far side of the bearing plate, a collar fixed to the drive member is included.Embodiment (I)The system described in.
  (10) The system of embodiment (9), wherein the collar contacts the proximal surface of the bearing plate with a maximum extension from the bearing plate at the distal end of the drive member.
[0045]
  (11) Further, a guide member that can be fixed to the handle is provided to give the patient abduction and forward tilt angle to the patient.Embodiment (I)The system described in.
  (12) In the embodiment (11), the guide member includes a leg, and the leg includes a first end coupled to the handle, and a second end from which the first and second arms extend. The system described.
  (13) The system of embodiment (12), wherein the first and second arms are substantially perpendicular to the legs.
  (14) The system of embodiment (12), wherein the first and second arms form an angle proportional to a selected anteversion angle relative to the second hole.
  (15) The system according to embodiment (12), wherein the leg portion of the guide is effective to form an angle corresponding to a predetermined abduction angle with respect to the second hole with the handle.
[0046]
  (16) The handle further includes a rotatable member that can be coupled to the first end of the guide member leg, the rotatable member being fixed to an intermediate portion of the handle, and about a long axis of the handle. The system of embodiment (12), wherein the system can be selectively rotated.
  (17) The system according to embodiment (16), wherein the guide member is rotatable around the handle so that each of the first and second arms can be arranged with respect to the long axis of the drive member. .
  (18) The second portion of the bearing plate extends from the first portion of the bearing plate at an angle of about 5 degrees to about 45 degrees.Embodiment (I)The system described in.
  The system of claim 18 wherein the angle formed by the handle and drive member substantially corresponds to the angle formed by the first and second portions of the bearing plate.
  (20) The handle and the drive member form an angle between about zero degrees and about 45 degrees.Embodiment (I)The system described in.
[0047]
(II) an elongate drive member having a proximal end coupled to the drive mechanism and a distal end having a mounting plate, wherein the mounting plate can be coupled to each of a plurality of reamers for forming a second hole; Each reamer forms a hole of a different size;
  A bearing plate having a near surface, a far surface and an opening extending therebetween, the bearing plate further including first and second portions that are angled with respect to each other, a portion of the drive member being secured within the bore and Disposing the drive member relative to a bearing plate;
  A handle having a proximal end for operation by a user and a distal end fixed to the bearing plate;
  An already formed first, comprising at least one position-finding member that can be selectively coupled to the second portion of the bearing plate and provides a reference point for positioning a reamer relative to the first hole. A reamer system that forms a second hole in relation to the hole.
  (21) Each of the plurality of reamers has a different radius.Embodiment (II)The system described in.
  (22) The position search member includes a base portion and an upper portion, and the base portion has a post that extends from the base portion and is inserted into a corresponding bore formed in the bearing plate, and the upper portion has a first hole. Having an outer surface with a shape that fits the shapeEmbodiment (II)The system described in.
  (23) The system according to embodiment (22), wherein an outer surface of the position search member forms a part of a sphere.
  (24) The system according to embodiment (23), wherein the long axis of the drive member is substantially aligned with the center of the sphere formed in part by the outer surface of the position search member.
  (25) The position search member has a size corresponding to one size of each of the plurality of reamers.Embodiment (II)The system described in.
[0048]
  (26) Further, the position search member includes a plurality of position search members, and each of the position search members has a shape effective for positioning one of the plurality of reamers with respect to the first hole.Embodiment (II)The system described in.
  (27) An embodiment in which each of the plurality of position search members has an outer surface forming a part of a sphere, and the center of each position search member is aligned with the long axis of the drive member when fixed to the bearing plate. The system according to (26).
  (28) The distal end of the drive member can move axially between a first position close to the bearing plate and a second position at a selected distance from the bearing plate.Embodiment (II)The system described in.
  (29) Further, a collar fixed to the drive member is included to limit the movement of the distal end of the drive member away from the bearing plate.Embodiment (II)The system described in.
[0049]
【The invention's effect】
As described above, according to the present invention, there is an effect that it is possible to provide a reamer system capable of forming a complicated hole that accurately fits the outer surface of the elliptical acetabular cup.
[Brief description of the drawings]
1A is a perspective view of a prior art elliptical acetabular cup, and FIG. 1B is a cross-sectional view of a prior art acetabular cup of FIG. 1A taken along line 1B-1B.
FIG. 2 is a perspective view of a prior art reamer / driver instrument.
FIG. 3 is a perspective view of a prior art basket reamer.
FIG. 4 is a perspective view of a reamer system according to the present invention in a first position.
FIG. 5 is a perspective view of the reamer system of FIG. 4 in a second position.
6 is a side view of the reamer system of FIG. 4 in a first position.
7 is a side view of the reamer system of FIG. 4 in a second position.
FIG. 8 is a front view of the reamer system of FIG. 4;
9 is a top view of the reamer system of FIG.
10 is a partial cross-sectional side view of the remote portion of the reamer system of FIG.
11 is a front view of a drive member that forms part of the reamer system of FIG. 4;
12 is a side view of a bearing plate that forms part of the reamer system of FIG. 4;
13 is a side view of a position finding member that forms part of the reamer system of FIG. 4;
FIG. 14 is a perspective view of a series of reamers that form part of another embodiment of a reamer system according to the present invention.
FIG. 15 is a perspective view of a series of position location members that form part of another embodiment of a reamer system according to the present invention.
[Explanation of symbols]
22 True hole (first hole)
100 reamer system
104 Drive member
106a-106f reamer
108 Handle
110 Bearing plate
112 Near end of handle
113 Position search member
116 Far end of handle
118 First part
124
130 Second part
134 bore
136 Far end of drive member, far reamer coupling end
138 Far side
140 Mounting plate
146 Proximal end of drive member

Claims (15)

In a reamer system that forms a second hole in relation to the first hole,
An elongated handle having a proximal end and a distal end;
A bearing plate having a first portion coupled to the handle, a second portion, and further including a near surface and a distant surface;
At least one position finding member removably and replaceably attached to the bearing plate;
An elongate drive member coupled to the second portion of the bearing plate;
The drive member has a distal reamer coupling end and a proximal end coupled to a drive mechanism to rotate the drive member;
The far reamer coupling end can move axially toward and away from the far surface of the bearing plate ;
The reamer system further includes a guide member that can be fixed to the handle for providing a reamer abduction and anteversion angle to the patient, the guide member including a leg, and the leg includes the handle. A reamer system including a first end coupled to the first end and a second end from which the first and second arms extend .   The system of claim 1, further comprising a mounting plate at a distal end of the drive member, the mounting plate being connectable to the reamer.   The system of claim 1, further comprising a plurality of reamers, each reamer having a different outer dimension and an inner surface that can be coupled to a distal reamer coupling end of the drive member.   The system of claim 1, wherein the location member has a proximal portion coupled to the bearing plate and a distal portion having an outer surface, wherein at least a portion of the outer surface is substantially spherical.   The position search member has a proximal portion coupled to the bearing plate and a remote portion having an outer surface, at least a portion of the outer surface being substantially spherical, and the proximal end of the position search member is The system of claim 1, including at least one mounting post insertable into a bore formed in the bearing plate.   The system of claim 1, further comprising a collar secured to the drive member to limit disengagement of a distal reamer coupling end of the drive member from a distal surface of the bearing plate.   The system of claim 6, wherein the collar contacts a proximal surface of the bearing plate with a maximum extension from the bearing plate at a distal end of the drive member. The system of claim 1 , wherein the first and second arms are substantially perpendicular to the legs. The system of claim 1, wherein the first and second arm portions form an angle that is proportional to the tilt angle before selected for the second hole. The system of claim 1 , wherein the guide leg is effective to form an angle with the handle corresponding to a predetermined abduction angle relative to the second hole. The handle further includes an alignment block coupleable with a first end of the guide member leg, the alignment block being fixed to an intermediate portion of the handle and selectively rotatable about a long axis of the handle. The system of claim 1 . The system of claim 11 , wherein the guide member is rotatable about the handle such that each of the first and second arms can be positioned with respect to the long axis of the drive member.   The system of claim 1, wherein the second portion of the bearing plate extends from the first portion of the bearing plate at an angle of 5 degrees to 45 degrees. The system of claim 13 , wherein the angle formed by the handle and drive member substantially corresponds to the angle formed by the first and second portions of the bearing plate.   The system of claim 1, wherein the handle and the drive member form an angle between zero and 45 degrees.

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